U.S. patent application number 16/260826 was filed with the patent office on 2019-08-29 for fuel cell system.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Shuji KURITA, Yushi SUZUKI.
Application Number | 20190267659 16/260826 |
Document ID | / |
Family ID | 67550575 |
Filed Date | 2019-08-29 |
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United States Patent
Application |
20190267659 |
Kind Code |
A1 |
KURITA; Shuji ; et
al. |
August 29, 2019 |
FUEL CELL SYSTEM
Abstract
A fuel cell system that can prevent impurities from intensively
collecting near inlets of fuel cells. The fuel cell system includes
a fuel cell stack formed by stacking fuel cells, each fuel cell
having a power generation portion, a stack manifold with a fuel gas
inlet communication hole disposed at an end of the fuel cell stack
in the stacking direction of the fuel cells, a mixed gas supply
channel communicating with the fuel gas inlet communication hole
for supplying a mixed gas of a fuel gas and fuel off-gas to the
fuel cell stack, a stirring mixer for swirling the mixed gas
provided in the mixed gas supply channel, and a guide rib provided
on the inner wall of the fuel gas inlet communication hole of the
stack manifold, on the side opposite to the side of the power
generation portions of the fuel cells.
Inventors: |
KURITA; Shuji; (Toyota-shi,
JP) ; SUZUKI; Yushi; (Okazaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
67550575 |
Appl. No.: |
16/260826 |
Filed: |
January 29, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 8/04149 20130101;
H01M 8/04156 20130101; H01M 8/0662 20130101; H01M 8/04097 20130101;
H01M 2250/20 20130101; H01M 8/2457 20160201; H01M 8/241 20130101;
H01M 8/2483 20160201 |
International
Class: |
H01M 8/2483 20060101
H01M008/2483; H01M 8/2457 20060101 H01M008/2457; H01M 8/241
20060101 H01M008/241; H01M 8/04119 20060101 H01M008/04119 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2018 |
JP |
2018-030325 |
Claims
1. A fuel cell system comprising: a fuel cell stack formed by
stacking a plurality of fuel cells, each fuel cell having a power
generation portion; a stack manifold that is disposed at an end of
the fuel cell stack in a stacking direction of the fuel cells and
that has at least a fuel gas inlet communication hole; a mixed gas
supply channel that communicates with the fuel gas inlet
communication hole of the stack manifold and that is adapted to
supply a mixed gas of a fuel gas and fuel off-gas to the fuel cell
stack; a stirring mixer that is provided in the mixed gas supply
channel and that is adapted to swirl the mixed gas; and a guide rib
that is provided on an inner wall of the fuel gas inlet
communication hole of the stack manifold, on a side opposite to a
side of the power generation portions of the fuel cells.
2. The fuel cell system according to claim 1, wherein the stirring
mixer is provided in the mixed gas supply channel in a position
immediately before the fuel gas inlet communication hole.
3. The fuel cell system according to claim 1, wherein the guide rib
is disposed such that it is perpendicular to a flow of impurities
contained in the mixed gas.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from Japanese patent
application JP 2018-030325 filed on Feb. 23, 2018, the content of
which is hereby incorporated by reference into this
application.
BACKGROUND
Technical Field
[0002] The present disclosure relates to a fuel cell system.
Background Art
[0003] As a conventional technique in this field, there has been
known a fuel cell system that includes a fuel cell stack formed by
stacking a plurality of fuel cells, a fuel gas supply channel that
is adapted to supply a fuel gas such as hydrogen to the fuel cell
stack, and a circulation channel that is adapted to reflux a fuel
off-gas (that is, an unconsumed fuel gas) that has been discharged
from the fuel cell stack to the fuel gas supply channel. In the
fuel cell system with such a configuration, the fuel off-gas
flowing through the circulation channel may possibly contain
produced water that has not been fully separated from the off-gas
by a gas-liquid separator and impurities, such as metal powder,
that have stuck during processes such as assembly of the fuel cell
stack. Further, if such impurities enter the fuel cell stack along
with the fuel gas flow, the power generating capability of the fuel
cells may be deteriorated.
[0004] To solve such a problem, various systems have been
considered. For example, JP 2009-164136 A discloses a fuel cell
system in which a fuel gas and fuel off-gas are made to flow
through the inside of a fuel gas supply channel and another flow is
further forced to be generated therein, thereby stirring the gas
flow so that impurities contained in the fuel off-gas become evenly
present therein, and the fuel off-gas with the impurities evenly
present therein is then supplied to a fuel cell stack (for example,
paragraph 0102 of JP 2009-164136 A).
SUMMARY
[0005] However, in the aforementioned fuel cell system, since the
flow generated with the incoming fuel off-gas in the fuel gas
supply channel becomes spiral, impurities contained in the fuel
off-gas may intensively collect near the inlets of the fuel
cells.
[0006] The present disclosure has been made so as to solve such a
technical problem, and provides a fuel cell system that can prevent
impurities from intensively collecting near the inlets of the fuel
cells.
[0007] According to the present disclosure, there is provided a
fuel cell system that includes a fuel cell stack formed by stacking
a plurality of fuel cells, each fuel cell having a power generation
portion; a stack manifold that is disposed at an end of the fuel
cell stack in the stacking direction of the fuel cells and that has
at least a fuel gas inlet communication hole; a mixed gas supply
channel that communicates with the fuel gas inlet communication
hole of the stack manifold and that is adapted to supply a mixed
gas of a fuel gas and fuel off-gas to the fuel cell stack; a
stirring mixer that is provided in the mixed gas supply channel and
that is adapted to swirl the mixed gas; and a guide rib that is
provided on an inner wall of the fuel gas inlet communication hole
of the stack manifold, on a side opposite to a side of the power
generation portions of the fuel cells.
[0008] In the fuel cell system according to the present disclosure,
since the stirring mixer is provided in the mixed gas supply
channel, impurities contained in a mixed gas flow toward the side
of the fuel cell stack while swirling by the stirring mixer, and
the impurities contained in the mixed gas can be moved to the side
opposite to the side of the power generation portions of the fuel
cells. In addition, since the guide rib is provided on the inner
wall of the fuel gas inlet communication hole of the stack
manifold, on the side opposite to the side of the power generation
portions of the fuel cells, the impurities contained in the mixed
gas are further blocked by the guide rib so that they collect at
the guide rib. As a result, it becomes possible to prevent the
impurities from intensively collecting near the inlets of the fuel
cells and to more widely diffuse the impurities in the mixed
gas.
[0009] In some embodiments of the fuel cell system according to the
present disclosure, the stirring mixer is provided in the mixed gas
supply channel in a position immediately before the fuel gas inlet
communication hole. With such a configuration, impurities contained
in a mixed gas can be efficiently moved to the side opposite to the
side of the power generation portions of the fuel cells.
[0010] In some embodiments of the fuel cell system according to the
present disclosure, the guide rib is disposed such that it is
perpendicular to the flow of impurities contained in the mixed gas.
With such a configuration, it is possible to effectively prevent
impurities from intensively collecting near the inlets of the fuel
cells.
[0011] According to the present disclosure, it is possible to
prevent impurities from intensively collecting near the inlets of
the fuel cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic configuration diagram of a fuel cell
system according to an embodiment;
[0013] FIG. 2 shows perspective views of a fuel cell stack and a
stack manifold;
[0014] FIG. 3 is a schematic view for illustration of how a
stirring mixer and a guide rib are arranged; and
[0015] FIG. 4 is a graph that shows the results of comparison
between Examples and Comparative Example.
DETAILED DESCRIPTION
[0016] An embodiment of the fuel cell system according to the
present disclosure will be described below with reference to the
drawings. The fuel cell system according to the present disclosure
may be mounted on and used as a drive source for vehicles, vessels,
aircrafts, trains, and the like, or used for a power generation
facility of buildings.
[0017] FIG. 1 is a schematic configuration diagram of a fuel cell
system according to an embodiment, and FIG. 2 shows perspective
views of a fuel cell stack and a stack manifold. A fuel cell system
1 of the present embodiment mainly includes a fuel cell stack 10,
an oxidant gas supply system 20 that is adapted to supply an
oxidant gas such as air to the fuel cell stack 10, and a fuel gas
supply system 30 that is adapted to supply a fuel gas such as
hydrogen to the fuel cell stack 10.
[0018] The fuel cell stack 10 is a cell stack formed by stacking a
plurality of fuel cells 11 and is a polymer electrolyte fuel cell.
Though not shown, each fuel cell 11 has, for example, a membrane
electrode assembly (MEA) including an ion-permeable electrolyte
membrane and a catalyst layer on the anode side (or an anode
electrode) and a catalyst layer on the cathode side (or a cathode
electrode) that sandwich the electrolyte membrane. Each fuel cell
11 further includes a pair of separators (that is, separators on
the anode and cathode sides) that sandwich the MEA.
[0019] Further, gas diffusion layers (GDLs), which are adapted to
supply a fuel gas or an oxidant gas to the fuel cells and also to
collect electricity generated through an electrochemical reaction,
may occasionally be further formed on the opposite sides of the
MEA. In this case, the MEA with the GDLs disposed on the opposite
sides thereof is referred to as a membrane electrode and gas
diffusion layer assembly (MEGA). The MEGA is further sandwiched
between the aforementioned separators on the anode and cathode
sides. Further, if the MEA has the GDLs, the MEA with the GDLs,
that is, the MEGA, is a power generation portion 111 of each fuel
cell 11. Meanwhile, if the MEA does not have the GDLs, the MEA is
the power generation portion 111 of each fuel cell 11.
[0020] As shown in FIG. 2, the power generation portion 111 is
disposed in a substantially center position of each fuel cell 11. A
fuel gas inlet communication hole 112a, refrigerant outlet
communication hole 112b, and oxidant gas outlet communication hole
112c are provided in this order on one side (the upper side in FIG.
2) and an oxidant gas inlet communication hole 112d, refrigerant
inlet communication hole 112e, and fuel gas outlet communication
hole 112f are provided in this order on the other side (the lower
side in FIG. 2) across the power generation portion 111 of each
fuel cell 11. These communication holes 112a to 112f are also
referred to as manifold holes and are each formed in a rectangular
shape.
[0021] Further, a stack manifold 12 is disposed at one end of the
fuel cell stack 10 in the stacking direction of the fuel cells 11.
The stack manifold 12 is formed in a substantially rectangular
plate shape with, for example, a metal material such as aluminum,
and securely fastened to the fuel cell stack 10 with bolts or the
like. The stack manifold 12 is provided with a fuel gas inlet
communication hole 12a, refrigerant outlet communication hole 12b,
oxidant gas outlet communication hole 12c, oxidant gas inlet
communication hole 12d, refrigerant inlet communication hole 12e,
and fuel gas outlet communication hole 12f in positions that
respectively correspond to the fuel gas inlet communication hole
112a, refrigerant outlet communication hole 112b, oxidant gas
outlet communication hole 112c, oxidant gas inlet communication
hole 112d, refrigerant inlet communication hole 112e, and fuel gas
outlet communication hole 112f of each fuel cell 11.
[0022] These communication holes 12a to 12f are each formed in a
rectangular shape in the same size as that of their respective
communication holes 112a to 112f provided in each fuel cell 11.
[0023] As shown in FIG. 1, the oxidant gas supply system 20
includes, for example, an oxidant gas supply channel 21 that is
adapted to supply an oxidant gas to the cathode electrode of the
fuel cell stack 10, and an oxidant gas discharge channel 22 that is
adapted to discharge, from the fuel cell stack 10, an oxidant
off-gas generated after an oxidant gas has been supplied to the
fuel cell stack 10 and used for an electrochemical reaction in each
fuel cell 11. The oxidant gas supply channel 21 communicates with
the oxidant gas inlet communication hole 12d of the stack manifold
12 and then with the oxidant gas inlet communication hole 112d of
each fuel cell 11. The oxidant gas discharge channel 22
communicates with the oxidant gas outlet communication hole 12c of
the stack manifold 12 and then with the oxidant gas outlet
communication hole 112c of each fuel cell 11.
[0024] The oxidant gas supply channel 21 and oxidant gas discharge
channel 22 are each made of, for example, a hose, pipe, and joint
member. Further, the oxidant gas supply channel 21 is provided with
an air cleaner 23, air compressor 24, intercooler 25, valve, and
the like. The oxidant gas discharge channel 22 is provided with a
muffler 26, valve, and the like.
[0025] Meanwhile, the fuel gas supply system 30 includes, for
example, a fuel gas supply source 31 that stores a high-pressure
fuel gas such as hydrogen, a fuel gas supply channel 32 that is
adapted to supply the fuel gas from the fuel gas supply source 31
to the anode electrode of the fuel cell stack 10, a circulation
channel 33 that is adapted to reflux a fuel off-gas (that is, an
unconsumed fuel gas) that has been discharged from the fuel cell
stack 10 to the fuel gas supply channel 32, and a fuel gas
discharge channel 34 that branches from the circulation channel 33
and that is adapted to discharge the fuel off-gas flowing through
the circulation channel 33 to the outside. The fuel gas supply
channel 32, circulation channel 33, and fuel gas discharge channel
34 are each made of, for example, a hose, pipe, and joint member.
Though not shown, the fuel gas supply channel 32 is provided with a
pressure gauge, injector, regulator, valve, and the like.
[0026] One end of the circulation channel 33 on its upstream side
(that is, the side of the fuel cell stack 10) communicates with the
fuel gas outlet communication hole 12f of the stack manifold 12 and
then with the fuel gas outlet communication hole 112f of each fuel
cell 11. The circulation channel 33 is provided with a gas-liquid
separator 35, hydrogen circulation pump 36, and the like. The
gas-liquid separator 35 is adapted to separate produced water (that
is, liquid water) from the fuel-off gas flowing through the
circulation channel 33 and store it. The aforementioned fuel gas
discharge channel 34 is provided such that it branches from the
circulation channel 33 at the gas-liquid separator 35. The hydrogen
circulation pump 36 is supplied with the fuel off-gas obtained
after gas-liquid separation at the gas-liquid separator 35 and
refluxes it to the fuel gas supply channel 32.
[0027] The circulation channel 33 is connected to the fuel gas
supply channel 32 via a junction pipe 37. The junction pipe 37 is
adapted to merge the fuel gas supplied from the fuel gas supply
source 31 with the fuel off-gas supplied from the circulation
channel 33, and to deliver the merged gas to the fuel cell stack
10. Therefore, the fuel gas supplied from the fuel gas supply
source 31 and the fuel off-gas supplied from the circulation
channel 33 are mixed together at the junction pipe 37 so as to
become a mixed gas. The mixed gas then flows into the fuel cell
stack 10 via a mixed gas supply channel 38.
[0028] The mixed gas supply channel 38 is a part of the fuel gas
supply channel 32, that is, a section of the fuel gas supply
channel 32 between the junction pipe 37 and the stack manifold 12.
Further, one end of the mixed gas supply channel 38 on its
downstream side (that is, the side of the fuel cell stack 10)
communicates with the fuel gas inlet communication hole 12a of the
stack manifold 12 and then with the fuel gas inlet communication
hole 112a of each fuel cell 11.
[0029] Though not shown, the fuel cell system 1 of the present
embodiment further includes a refrigerant supply channel that is
adapted to supply a refrigerant to the fuel cell stack 10 and a
refrigerant discharge channel that is adapted to circulate a
refrigerant discharged from the fuel cell stack 10 to the side of a
radiator. The refrigerant supply channel communicates with the
refrigerant inlet communication hole 12e of the stack manifold 12
and then with the refrigerant inlet communication hole 112e of each
fuel cell 11. The refrigerant discharge channel communicates with
the refrigerant outlet communication hole 12b of the stack manifold
12 and then with the refrigerant outlet communication hole 112b of
each fuel cell 11.
[0030] Further, the mixed gas supply channel 38 is provided with a
stirring mixer 39 that is adapted to stir the mixed gas of the fuel
gas and fuel off-gas. Specifically, as shown in FIG. 3, the
stirring mixer 39 is disposed inside a pipe that forms the mixed
gas supply channel 38, and may be rotatably driven by a motor (not
shown) that is disposed outside the pipe, so that a rotational
force is applied to the mixed gas flowing through the mixed gas
supply channel 38. Herein, the stirring mixer 39 may be provided in
a position immediately before the fuel gas inlet communication hole
12a of the stack manifold 12 in the mixed gas supply channel
38.
[0031] Furthermore, as shown in FIG. 3, a guide rib 13 is provided
on the inner wall of the fuel gas inlet communication hole 12a of
the stack manifold 12, on the side opposite to the side of the
power generation portions 111 of the fuel cells 11. The guide rib
13 is formed in a plate shape with a resin material, for example,
and is secured, with an adhesive or the like, to the side (the
upper side in FIG. 3) opposite to the side of the power generation
portions 111 on the inner wall of the fuel gas inlet communication
hole 12a. The guide rib 13 may be disposed such that it is
perpendicular to the flow of impurities contained in the mixed
gas.
[0032] In the fuel cell system 1 with the aforementioned
configuration, since the stirring mixer 39 is provided in the mixed
gas supply channel 38, impurities contained in the mixed gas flow
toward the fuel cell stack 10 while swirling by the stirring mixer
39 as indicated by an arrow F of FIG. 3, and the impurities
contained in the mixed gas can be moved to the side (the upper side
in FIG. 3) opposite to the side of the power generation portions
111 of the fuel cells 11.
[0033] In addition, since the guide rib 13 is provided on the inner
wall of the fuel gas inlet communication hole 12a of the stack
manifold 12, on the side opposite to the side of the power
generation portions 111 of the fuel cells 11, the impurities
contained in the mixed gas are further blocked by the guide rib 13
so that they collect at the guide rib 13. As a result, it becomes
possible to prevent the impurities from intensively collecting near
the inlets of the fuel cells 11 and to more widely diffuse the
impurities in the mixed gas (see the arrow F of FIG. 3).
[0034] Further, in the fuel cell system 1 of the present
embodiment, since the stirring mixer 39 is provided in the mixed
gas supply channel 38 in a position immediately before the fuel gas
inlet communication hole 12a, the impurities contained in the mixed
gas can be efficiently moved to the side opposite to the side of
the power generation portions 111 of the fuel cells 11.
Furthermore, since the guide rib 13 is disposed such that it is
perpendicular to the flow of the impurities contained in the mixed
gas, it is possible to effectively prevent the impurities from
intensively collecting near the inlets of the fuel cells 11.
[0035] To verify the advantageous effects of the present
disclosure, the inventors prepared, using the aforementioned fuel
cell system 1, Comparative Example in which the guide rib is not
provided on the inner wall of the fuel gas inlet communication hole
of the stack manifold, on the side opposite to the side of the
power generation portions of the fuel cell stack, Example 1 in
which the guide rib is provided on the aforementioned side, and
Example 2 in which the guide rib is provided on the aforementioned
side such that it is perpendicular to the flow of liquid water
contained in the mixed gas. Further, liquid water with the highest
percentage of impurities was extracted from each of the
aforementioned Comparative Example, Example 1, and Example 2, and
the quantity of the liquid water extracted from each example was
measured.
[0036] FIG. 4 shows the results of comparison of Examples and
Comparative Example. FIG. 4 proves that in each of Examples 1 and
2, the quantity of the liquid water near the inlets of the fuel
cells was smaller than that of Comparative Example. Specifically,
as compared to Comparative Example, the quantity of liquid water of
Example 1 was smaller by about 21% and that of Example 2 was
smaller by about 35%. These results proved that liquid water can be
prevented from intensively collecting near the inlets of the fuel
cells when the guide rib is provided. Further, it was found that
the quantity of liquid water near the inlets of the fuel cells of
Example 2 was further smaller than that of Example 1. The foregoing
proved that the advantageous effect of preventing liquid water from
intensively collecting near the inlets of the fuel cells can be
further improved when the guide rib is provided such that it is
positioned perpendicular to the flow of the liquid water contained
in the mixed gas.
[0037] Although the embodiment of the present disclosure has been
described in detail, the specific configuration is not limited
thereto, and any design changes are possible without departing from
the spirit and scope of the present disclosure described in the
claims. For example, the fuel cell stack may be further provided
with a dummy cell (a cell that does not generate electricity) in a
position adjacent to the stack manifold. Such a configuration can
provide the same operational advantages as those in the
aforementioned embodiment.
DESCRIPTION OF SYMBOLS
[0038] 1 Fuel cell system [0039] 10 Fuel cell stack [0040] 11 Fuel
cell [0041] 12 Stack manifold [0042] 12a Fuel gas inlet
communication hole [0043] 13 Guide rib [0044] 30 Fuel gas supply
system [0045] 32 Fuel gas supply channel [0046] 33 Circulation
channel [0047] 37 Junction pipe [0048] 38 Mixed gas supply channel
[0049] 39 Stirring mixer [0050] 111 Power generation portion [0051]
112a Fuel gas inlet communication hole
* * * * *